BRACHYURY (BRACHY) AND INSULIN LIKE GROWTH FACTOR RECEPTOR I (IGF1R) EXPRESSION IN THYROID NODULAR PATHOLOGY.

MARTÍN, AYELEN; PATRICIA PAPENDIEK; MEDIN, MARTIN; PATRICIA A. PENNISI; FERNANDEZ, MARÍA CELIA; CLEMENT, FLORENCIA; DI MATTEO; MASNATA , MARÍA; BARRIOS EVELYN; CHIESA A

Mar del Plata

Congreso; Reunion Anual de la Sociedad Argentina de Investigación Clínica; 2020

Sociedad Argentina de Investigación Clínica

In pediatrics, thyroid tumor stratification is difficult to assess. Ep-ithelial-mesenchymal transition (EMT), plays a role in tumor de-velopment. In human carcinomas Brachy has been identified as aregulator of EMT associated to malignancy. To date, no informationabout Brachy and IGF1R expression in pediatric thyroid nodulardisease is available. Aim: To evaluate Brachy and IGF1R expres-sion in thyroid nodular samples from pediatric patients and to studythe effect of Brachy overexpression in a thyroid papillary carcinoma(TPC) cell line in vitro. Methods: Paraffin-embedded samples frompediatric patients with Thyroid Papillary Carcinomas (TPCa), Follic-ular Adenomas (FA) or Benign Thyroid Nodular disease (BTN) wereprocessed for Brachy and IGF1R immunostaining. TPC cells wereused to obtain clones overexpressing Brachy (TPC. 50 and TPC.150). Gene expression was quantified by rqPCR. Proliferation as-says (6 days) and wounding assays (24h) were carried out. Proteinextracts were obtained from whole lysates and processed by west-ern blot (WB). Results: 43 samples were analysed, 10 from BTN.Only TPCa and FA showed positive staining for Brachy (16/25TP-Ca;5/8FA) and IGF1R (12/25TPCa;3/8FA). In carcinomas, positivi-ty for IGF1R was only detected when Brachy was present. Brachyoverexpression in TPCcells (TPC50) increased proliferation com-pared to parental cells (**p< 0.005). Cell migration was also higherfor Brachy overexpressing cells (**p< 0.005 TPC50 vs TPC), e-cad-herin expression was diminished, and mesenchymal markers (vi-mentin-fibronectin) were increased. Finally, WB studies showed thatBrachy overexpression was related to a higher IGF1R expression inTPC50 cells in comparison to parental cells. Conclusion: Brachyexpression was associated to IGF1R expression in thyroid carci-nomas. In vitro, Brachy overexpression had an impact on IGF1Rexpression, increased proliferation and migration. These resultssuggest a potential role for Brachy in the biology of thyroid tumors.